A mock-heroic sequel to his "Once Upon a Time in a Battlefield" (2003), Korean helmer Lee Joon-ik's "Battlefield Heroes" picks up the action (and the comedy) eight years later in 668 A.D.

A mock-heroic sequel to his “Once Upon a Time in a Battlefield” (2003), Korean helmer Lee Joon-ik’s “Battlefield Heroes” picks up the action (and the comedy) eight years later in 668 A.D. Lee excels at maintaining a wide spectrum of memorable, sharply delineated characters of different classes, advancing parallel storylines in which kings and generals scheme and double-cross, manipulating armies like chess pieces, while hapless conscripted peasants scramble to survive. After yielding disappointing Korean B.O. returns, “Heroes” caused the hitherto commercially successful Lee to announce his retirement (since recanted), but the film should shine on the fest circuit.

A newly hatched war positions the small southern Korean state of Shilla in a dangerous alliance with China’s Tang dynasty against the large northern state of Goguryeo, the film bitterly parodying North/South Korean relations in general and specific terms. One particularly hilarious scene sees the North Koreans catapulting live chickens, goats, pigs and cows over their ramparts into the bewildered South Korean camp in retaliation for the latter’s disconcerting offer of rice (an absurdist reference to food relief).

On the highest level, Shilla’s sardonic young king (Hwang Jeong-min) follows the counsel of his wily old general (Jeong Jin-yeong), who, rightfully distrustful of their superpower ally, withholds his main forces — the first strategic move in a long, cunning game against Tang treachery. On the northern side, Goguryeo’s fearsome general (Lee Weon-jong) dies, but not before bypassing his eldest, diplomatically inclined son (Yun Je-mun) in favor of his martial second-born (Ryu Seung-ryong), thus setting brother against brother; it’s the closest Lee ever comes to outright Shakespearean tragedy. But the helmer grants no inner conflict or humanity to the cold, villainous Tangs, united under a single autocratic general (Lee Dae-yeon).

Among the groundlings, the pic finds its true antic hero in Thingy (Lee Mun-shik), a peasant so poor he doesn’t own a name. A veteran of the earlier war chronicled in “Once Upon a Time in a Battlefield,” Thingy instructs his countrymen in the fine art of staying alive — by marching in place when others are advancing, for instance. Accidentally catapulted into the enemy stronghold, Thingy is persuaded to broadcast a heartfelt propaganda message to the southern army, expounding on the futility of war and the treachery of the Tangs; in exchange, he demands the hand of a feisty female warrior (Seon Woo-seon) in a subplot that plays like a coy feudal romantic comedy. All this transpires during sweeping epic battles in which mysterious secret weapons rain deadly projectiles upon formations of luckless soldiers.

Lee creates brilliantly stratified storylines, each with its own level of satire, slapstick or tragedy, and sustains them through a convoluted mix of action and class distinctions. The fixed nature of the siege dictates that the two sides deploy ever more devious, desperate measures as rocks, fire, animals, vegetables and humans are catapulted back and forth. Despite the huge cast, each character is immediately recognizable, his role in the overall drama never negligible in the ingenious script by producers Jo Cheol-hyeon and Oh Seung-hyeon. Sa Gong-heui’s production design combines historical scope with a measure of medieval whimsy.